1. Field of the Invention
The present invention relates to computer systems. More specifically, the present invention relates to techniques for decoding instructions in a central processing unit of a computer.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
2. Description of the Related Art
As is well known, computers execute a sequence of instructions which are provided to the central processing unit (CPU) thereof. The instructions are typically stored while being decoded and executed by the CPU. As the format of the instructions varies from one system to another, compatibility between systems presumes a capability on the part of the emulating system to decode instructions written for the emulated system. System compatibility is easily achieved by simply designing the emulating system in accordance with the design of the emulated system. However, this option may not be viable when the design of the emulated system is proprietary.
Thus, there is a need in the art for a system for decoding instructions on an emulating system to provide compatibility with an emulated system. In particular, there is a need for a novel system for decoding 808X instructions which does not encroach on the proprietary rights of others. One essential component of such a system would be a novel system for fetching instructions to be decoded. In addition, there is an ongoing need in the art for improvements in the speed of the decoding operation.